Presently, in surgical staplers, staples pass through guiding pockets by means of a driver to a forming surface. These pockets are generally long, rectangular channels through which pass the staples in an unformed state. A pocket conforms to the generally rectangular cross-sectional shape of the staple driver. When the staple passes through the pocket by force of the staple driver, it is guided down the pocket channel and onto the anvil of the stapler. It is at the anvil where the staple driver forms the staple. The staple driver remains in the pocket channel, during forming of the staple. The gap between the driver and the anvil is set so that generally most of the gap is filled by the staple.
Generally, the presently used pockets have a rectangular shape. That is, there are generally a first pair of parallel sides which are formed along the length of the unformed staple. This first pair of parallel sides is met by a second pair of parallel sides at right angles. This second pair of parallel sides generally corresponds to the width of the staple and staple driver.
However, when the staple passes through the generally rectangular-shaped pocket, it may cause the stapler to jam. This happens when the staple has been loaded in the pocket at an angle to the generally parallel sides of the pocket. When placed at this angle, the staple can be forced by the driver until the staple becomes wedged in the staple forming pocket or is misformed on the anvil.
The presently shaped staple pockets have other drawbacks, both in method of manufacture and in ease of operation. Because these staple pockets have the potential to be misloaded or to jam, it is generally desired to keep the tolerances between the forming pockets and the staples very close. This minimizes the chances of the staple being loaded and guided in the pocket in any other way except in a properly aligned fashion. However, when this is done, it is difficult to consistently manufacture the staple pockets to such close tolerances. This is very costly and time consuming. In addition, it is much more difficult to inspect the staple pockets to determine whether they have been maintained at the proper tolerances. Of course, if the tolerances are kept close, there is also the possibility that the staple pockets are manufactured to be too small for the staples.
Finally, one other disadvantage of the presently formed staple pockets is that they are difficult to load with staples. This is true because the staples that are misloaded tend to become jammed in the pockets, usually during contact with the staple driver. Because it is not plainly determinable whether the stables will jam within the pockets, the pockets frequently will retain some of the staples.